Method for removal of poisonous gases

ABSTRACT

Halogens and/or hydrogen halides in a gas can easily be removed from the gas by contacting the gas with an adsorbent comprising an activated carbon having as supported thereon (1) one or more components included in one of the three groups shown below and (2) one or more components included in the remaining two groups shown below: 
     
         ______________________________________                                    
 
    
     Group      Component                                                      
______________________________________                                    
I          copper compound                                                
II         zinc compound                                                  
III        (a) alkali metal compounds                                     
           (b) alkaline earth metal compounds                             
           (c) compounds of Al, Ti, V, Cr, Mn, Fe,                        
              Co, Ni, Cd and Pb                                           
______________________________________                                    
 .

This invention relates to a method of removing halogens and/or hydrogenhalides from gases containing the same.

Halogens and hydrogen halides are contained in process gases frompetrochemical and chemical plants, by-product gases from iron works,electrolytic hydrogen, steam for reforming and other various wastegases. Such halogens and hydrogen halides, which, even in trace amounts,are extremely poisonous to the human body, exert corrosive action onmetal surfaces of equipment, etc. and also exhibit catalyst poisonaction, often present problems in such processes as chemical reaction.

As the method of removing halogens and hydrogen halides in gases, therehave been proposed, for example, a procedure of washing with chemicalsolutions such as alkaline solutions, and an adsorption process with useof activated carbon, etc. However, these methods show inferior removaleffect, and a more efficient adsorbent has been demanded.

The present inventors, in view of these circumstances, conductedintensive investigation, and as a result, found that by having assupported on activated carbon two or more specific components selectedfrom (I) copper compounds, (II) zinc compounds and (III) (a) alkalimetal compounds, (b) alkaline earth metal compounds and (c) compounds ofAl, Ti, V, Cr, Mn, Fe, Co, Ni, Cd and Pb, halogens and hydrogen halidesin gases can be removed with enhanced efficiency, which has culminatedin the present invention.

Thus the present invention relates to:

1. A method for the removal of halogens and/or hydrogen halides from agas containing the same, which comprises contacting the gas with anadsorbent comprising an activated carbon having as supported thereon (1)one or more components included in one of the three groups shown belowand (2) one or more components included in the remaining two groupsshown below:

    ______________________________________                                        Group      Component                                                          ______________________________________                                        I          copper compounds                                                   II         zinc compounds                                                     III        (a) alkali metal compounds                                                    (b) alkaline earth metal compounds                                            (c) compounds of Al, Ti, V, Cr, Mn, Fe,                                       Co, Ni, Cd and Pb                                                  ______________________________________                                    

A copper compound in Group I is hereinafter referred to as Component I;a zinc compound in Group II is hereinafter referred to as Component II;a compound in Group III is hereinafter referred to as Component III; analkali metal compound in Group III is hereinafter referred to asComponent III-a; an alkaline earth metal compound in Group III ishereinafter referred to as Component III-b; and a compound of Al, Ti, V,Cr, Mn, Fe, Co, Ni, Cd or Pb is hereinafter referred to as ComponentIII-c.

The adsorbent used in the present invention can be prepared bysupporting on the activated carbon two or more of Component I, ComponentII and Component III.

The activated carbon which is useful in this case may be any type ofactivated carbon produced by the known processes from coal, coke, woodcharcoal, coconut shells, resins, etc., while its specific surface areais preferably within the range from 200 to 2000 m² /g. With reference toits shape and form, use is suitably made for example of spherical- andcylindrical-formed, crushed, powdered and fibrous-formed activatedcarbon according to the type of gas treatment methods.

Examples of the copper compound which is used as the Component I in thepresent invention include inorganic acid salts or inorganic compoundssuch as carbonates, basic carbonates, nitrates, sulfates, phosphates,halides, oxides and hydroxides; and organic acid salts such as formates,acetates and oxalates.

Examples of the zinc compound which is used as the Component II in thepresent invention include inorganic acid salts or inorganic compoundssuch as carbonates, basic carbonates, nitrates, sulfates, phosphates,silicates, halides, oxides and hydroxides; and organic acid salts suchas formates, acetates and oxalates.

As the alkali metal compound which is one of the Component III, theremay be mentioned inorganic compounds of Li, Na, K, Rb and Cs such ashydrogencarbonates, carbonates, nitrates, borates, silicates, sulfates,halides and hydroxides, organic acid salts thereof such as formates,acetates, oxalates, benzoates, salts with phenols and sulfonates, and soforth.

As the alkaline earth metal compound which is another Component III,there may be mentioned inorganic acid salts or inorganic compounds ofBe, Mg, Ca, Sr and Ba such as carbonates, nitrates, sulfates,phosphates, halides, oxides and hydroxides, organic acid salts thereofsuch as formates, acetates and oxalates, and the like.

Examples of the compounds of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cd and Pbwhich are another Component III include inorganic acid salts orinorganic compounds of these metals such as carbonates,hydrogencarbonates, nitrates, borates, silicates, sulfates, phosphates,halides, hydroxides, ammonium salts and oxides, and organic acid saltsthereof such as formates, acetates, oxalates, benzoates, salts withphenols and salts with sulfonic acids.

The adsorbent of the present invention comprises activated carbon havingtwo or more of the Components I, II and III contained therein. Morespecifically, as Component III, Component III-a, Component III-b andComponent III-c may be contained solely, respectively, and out of these,two kinds of such components, for example the Components III-a andIII-b, the Components III-b and III-c and the Components III-c andIII-a, may be contained, though the Components III-a, III-b and III-c,may be contained simultaneously. In addition, not less than two types ofdifferent components within the components of the same kind may becontained; thus, for example, not less than two kinds of compounds maybe contained as the Component I, not less than two kinds of compoundsmay be contained as the Component II, and not less than two kinds ofdifferent compounds within the Component III-a may be contained as theComponent III.

The content of Component I in activated carbon containing the metalcompounds is 0.1 mg-atom to 3.0 mg-atom as metal per g of activatedcarbon, preferably 0.2 mg-atom to 2.0 mg-atom. The content of ComponentII is 0.1 mg-atom to 3.0 mg-atom as metal per g of activated carbon,preferably 0.2 mg-atom to 2.0 mg-atom. The content of Component III is0.1 mg-atom to 5.0 mg-atom as metal per g of activated carbon,preferably 0.2 mg-atom to 4.0 mg-atom.

The adsorbent used in the present invention may comprise activatedcarbon having each of the components as supported or deposited thereon,and may be those obtained by adding each component to a raw material foractivated carbon and then activating it. The adsorbent may also be thoseobtainable by adding a part of each of Components I, II and III to a rawmaterial for activated carbon and activating it, followed by depositionof the remainder of each of the components. In cases in which each ofthe Components is deposited on activated carbon, it is desirable toconduct drying or calcining after deposition.

As the procedure of depositing each of the components on activatedcarbon, a process of impregnating or spraying activated carbon with asolution or suspension of individual components in water (inclusive ofaqueous acid or alkali solution) or various solvents may be conceivable.In the preparation process described hereinbefore, the term "drying"denotes a step in which the water or solvent in the activated carbonhaving the components deposited is evaporated at a temperature of nothigher than about 130° C., while the term "calcining" means a step inwhich the activated carbon having the components deposited after beingdried at a temperature of not lower than about 130° C. is heated in anatmosphere of inert gas, carbonic acid gas, steam, combustion waste gas,etc. to decompose thermally part or all of the metal compounds.

In the above-mentioned process, when compounds other than oxides aredeposited on activated carbon as Component I, Component II and ComponentIII (exclusive of the alkali metal compounds), it is desirable toconduct heat treatment such as drying or calcining after deposition, andin cases in which Component I, Component II and Component III (exclusiveof the alkali metal compounds) are deposited on activated carbon withoutheat treatment, it is recommended to use oxides as Component I,Component II and Component III (exclusive of the alkali metalcompounds). In cases where alkali metal compounds other than hydroxides,carbonates and hydrogencarbonates of alkali metals are deposited onactivated carbon as Component III, it is preferred to conduct heattreatment such as drying or calcining after deposition, and when thealkali metal compounds are deposited without subsequent heat treatment,it is desirable to employ hydroxides, carbonates and hydrogen-carbonatesas the alkali metal compounds.

In the present invention, the term "halogens" represents F₂, Cl₂, Br₂and I₂, and the term "hydrogen halides" denotes HF, HCl, HBr and HI.

In the present invention, a gas containing halogens and hydrogen halidesmay be contacted with the adsorbent.

As the technique of contacting, use is made for example of the knownmeans such as fixed bed, moving bed and fluidized bed. In such cases,the contact temperature is not higher than 600° C., preferably 0° to300° C., and the pressure is not more than 300 kg/cm², preferably 0.1 to250 kg/cm². The contact time is 1/10 to 100 seconds as converted at 25°C. and 1 kg/cm², preferably 1/5 to 80 seconds.

The examples are described below to illustrate the present inventionmore specifically.

EXAMPLE 1

Activated carbon A₀ of 16 to 24 mesh having a BET specific surface areaof 1150 m² /g was sprayed uniformly with solutions in water of thedesired amount of each of the Component I (copper nitrate) and ComponentII (zinc nitrate) and/or Component III (nitrates of alkali metals,nitrates of alkaline earth metals and nitrates of Al, Ti, V, Cr, Mn, Fe,Co, Ni, Cd and Pb (sulfate only for V)).

50 ml each of the resulting deposited products were packed into columnsof 4 cm in diameter made of quartz glass, and the columns were heated ata heating rate of 5° C./min, while passing a nitrogen gas through eachof them at a linear flow rate of 10 cm/sec, to conduct calcining at 300°C. for 30 minutes.

The content of each of the metal compounds in the resulting adsorbentswere 0.2 to 2.0 mg-atom as individual metal per g of activated carbon,as shown in Table 1.

As the control references, activated carbon A₀ was deposited with anitrate of each of the metals alone, and calcined in nitrogen gas at300° C. for 30 minutes to prepare adsorbents.

15 ml each of the adsorbents thus obtained were packed into columns of1.6 cm in diameter made of glass, and a gas (97.5 vol. % of N₂ and 2.5vol.% of H₂ O) containing 20 ppm of HCl and 10 ppm of Cl₂ was passedthrough the individual columns at a linear flow rate of 40 cm/sec (asconverted at 30° C.) at 200° C. to check the changes of removal ratiofor HCl--Cl₂ (as converted to the total Cl) in relation to time. Theresults are shown in Table 1.

EXAMPLE 2

Packed into columns of 1.6 cm in diameter made of glass were 15 ml eachof the adsorbents A₀, A₁, A₃, A₉, A₁₂, B₂, B₃, C₄, C₆, C₉, D₂, D₃, D₈,D₁₀, D₁₂, D₁₃, D₁₄, D₁₅, E₂, E₃, E₄, F₁, F₆, F₉, G₁, G₂, G₃, G₆, G₈ andG₁₀ shown in Table 1 and a gas (8 vol.% of H₂ and 92 vol.% of N₂) of 30°C. containing 20 ppm of HCl and 10 ppm of Cl₂ was passed through theindividual columns at a linear flow rate of 40 cm/sec to check thechanges of removal ratio for HCl--Cl₂ (as converted to the total Cl) inrelation to time. The results are shown in Table 2.

                                      TABLE 1                                     __________________________________________________________________________             Components supported on activated                                             carbon and their amount                                                       (mg-atom/g)         Percent removal of HCl and Cl.sub.2 at                    Component                                                                           Component                                                                           Component                                                                             the elapsed time shown below (%)                 Adsorbent No.                                                                          I     II    III     5 hrs.                                                                             10 hrs.                                                                           20 hrs.                                                                           50 hrs.                             __________________________________________________________________________    A.sub.0 (Control)                                                                      --    --    --       15   2   0   0                                  A.sub.1 (Control)                                                                      Cu-2.0                                                                              --    --      100  100  65  0                                  A.sub.2 (Control)                                                                      --    --    Na-2.0  100   98  5   0                                  A.sub.3 (Control)                                                                      --    --    K-2.0   100  100  17  0                                  A.sub.4 (Control)                                                                      --    --    Mg-2.0  100   90  3   0                                  A.sub.5 (Control)                                                                      --    --    Ca-2.0  100   85  3   0                                  A.sub.6 (Control)                                                                      --    --    Sr-2.0  100   79  5   0                                  A.sub.7 (Control)                                                                      --    --    Al-2.0  100   85  5   0                                  A.sub.8  (Control)                                                                     --    --    Cr-2.0  100   92  15  0                                  A.sub.9 (Control)                                                                      --    --    Fe-2.0  100  100  30  0                                  A.sub.10 (Control)                                                                     --    --    Ni-2.0  100  100  52  0                                  A.sub.11 (Control)                                                                     --    --    Pb-2.0  100   95  10  0                                  A.sub.12 (Control)                                                                     --    Zn-2.0                                                                              --      100  100  75  0                                  B.sub.1 (The present                                                                   Cu-1.0                                                                              --    Na-1.0  100  100 100 18                                  invention)                                                                    B.sub.2 (The present                                                                   Cu-1.0                                                                              --    K-1.0   100  100 100 26                                  invention)                                                                    B.sub.3 (The present                                                                   Cu-1.0                                                                              --    Mg-1.0  100  100 100  5                                  invention)                                                                    B.sub.4 (The present                                                                   Cu-1.0                                                                              --    Ca-1.0  100  100 100 10                                  invention)                                                                    B.sub.5 (The present                                                                   Cu-1.0                                                                              --    Sr-1.0  100  100 100 13                                  invention)                                                                    C.sub.1 (The present                                                                   Cu-1.0                                                                              --    Al-1.0  100  100 100 32                                  invention)                                                                    C.sub.2 (The present                                                                   Cu-1.0                                                                              --    Ti-1.0  100  100 100 40                                  invention)                                                                    C.sub.3 (The present                                                                   Cu-1.0                                                                              --    V-1.0   100  100 100 18                                  invention)                                                                    C.sub.4 (The present                                                                   Cu-1.0                                                                              --    Cr-1.0  100  100 100 85                                  invention)                                                                    C.sub.5 (The present                                                                   Cu-1.0                                                                              --    Mn-1.0  100  100 100 69                                  invention)                                                                    C.sub.6 (The present                                                                   Cu-1.0                                                                              --    Fe-1.0  100  100 100 80                                  invention)                                                                    C.sub.7 (The present                                                                   Cu-1.0                                                                              --    Co-1.0  100  100 100 75                                  invention)                                                                    C.sub.8 (The present                                                                   Cu-1.0                                                                              --    Ni-1.0  100  100 100 75                                  invention)                                                                    C.sub.9 (The present                                                                   Cu-1.0                                                                              Zn-1.0                                                                              --      100  100 100 88                                  invention)                                                                    C.sub.10 (The present                                                                  Cu-1.0                                                                              --    Cd-1.0  100  100 100 15                                  invention)                                                                    C.sub.11 (The present                                                                  Cu-1.0                                                                              --    Pb-1.0  100  100 100 23                                  invention)                                                                    C.sub.12 (The present                                                                  Cu-0.2                                                                              --    Cr-1.0  100  100  85  3                                  invention)                                                                    C.sub.13 (The present                                                                  Cu-0.5                                                                              --    Cr-1.0  100  100  95  4                                  invention)                                                                    C.sub.14 (The present                                                                  Cu-2.0                                                                              --    Cr-1.0  100  100 100 93                                  invention)                                                                    D.sub.1 (The present                                                                   Cu-1.0                                                                              --    Na-0.3, Al-0.5                                                                        100  100 100 86                                  invention)                                                                    D.sub.2 (The present                                                                   Cu-1.0                                                                              --    K-0.3, V-0.5                                                                          100  100 100 90                                  invention)                                                                    D.sub.3 (The present                                                                   Cu-1.0                                                                              --    K-0.3, Cr-0.5                                                                         100  100 100 100                                 invention)                                                                    D.sub.4 (The present                                                                   Cu-1.0                                                                              --    K-0.3, Mn-0.5                                                                         100  100 100 99                                  invention)                                                                    D.sub.5 (The present                                                                   Cu-1.0                                                                              --    K-0.3, Fe-0.5                                                                         100  100 100 100                                 invention)                                                                    D.sub.6 (The present                                                                   Cu-1.0                                                                              --    Mg-0.3, Co-0.5                                                                        100  100 100 98                                  invention)                                                                    D.sub.7 (The present                                                                   Cu-1.0                                                                              --    Ca-0.3, Ni-0.5                                                                        100  100 100 100                                 invention)                                                                    D.sub.8 (The present                                                                   Cu-1.0                                                                              Zn-0.5                                                                              K-0.3   100  100 100 100                                 invention)                                                                    D.sub.9 (The present                                                                   Cu-1.0                                                                              --    Na-0.3, Cd-0.5                                                                        100  100 100 100                                 invention)                                                                    D.sub.10 (The present                                                                  Cu-1.0                                                                              --    K-0.3, Pb-0.5                                                                         100  100 100 85                                  invention)                                                                    D.sub.11 (The present                                                                  Cu-0.2                                                                              --    K-0.3, Cr-0.5                                                                         100  100 100 46                                  invention)                                                                    D.sub.12 (The present                                                                  Cu-0.5                                                                              --    K-0.3, Mn-0.5                                                                         100  100 100 58                                  invention)                                                                    D.sub.13 (The present                                                                  Cu-0.2                                                                              --    Mg-0.5, Cr-0.5                                                                        100  100 100 48                                  invention)                                                                    D.sub.14 (The present                                                                  Cu-0.5                                                                              --    Mg-0.5, Cr-0.5                                                                        100  100 100 100                                 invention)                                                                    D.sub.15 (The present                                                                  Cu-1.0                                                                              --    K-0.3, Mg-0.3                                                                         100  100 100 100                                 invention)                                                                                         Cr-0.5, Fe-0.25                                          E.sub.1 (The present                                                                   --    Zn-1.0                                                                              Na-1.0  100  100 100 20                                  invention)                                                                    E.sub.2 (The present                                                                   --    Zn-1.0                                                                              K-1.0   100  100 100 30                                  invention)                                                                    E.sub.3 (The present                                                                   --    Zn-1.0                                                                              Mg-1.0  100  100 100 35                                  invention)                                                                    E.sub.4 (The present                                                                   --    Zn-1.0                                                                              Ca-1.0  100  100 100 100                                 invention)                                                                    E.sub.5 (The present                                                                   --    Zn-1.0                                                                              Sr-1.0  100  100 100 25                                  invention)                                                                    F.sub.1 (The present                                                                   --    Zn-1.0                                                                              Al-1.0  100  100 100 30                                  invention)                                                                    F.sub.2 (The present                                                                   --    Zn-1.0                                                                              Ti-1.0  100  100 100 25                                  invention)                                                                    F.sub.3 (The present                                                                   --    Zn-1.0                                                                              V-1.0   100  100 100 20                                  invention)                                                                    F.sub.4 (The present                                                                   --    Zn-1.0                                                                              Cr-1.0  100  100 100 95                                  invention)                                                                    F.sub.5 (The present                                                                   --    Zn-1.0                                                                              Mn-1.0  100  100 100 63                                  invention)                                                                    F.sub.6 (The present                                                                   --    Zn-1.0                                                                              Fe-1.0  100  100 100 75                                  invention)                                                                    F.sub.7 (The present                                                                   --    Zn-1.0                                                                              Co-1.0  100  100 100 65                                  invention)                                                                    F.sub.8 (The present                                                                   --    Zn-1.0                                                                              Ni-1.0  100  100 100 80                                  invention)                                                                    F.sub.9 (The present                                                                   --    Zn-1.0                                                                              Cd-1.0  100  100 100 55                                  invention)                                                                    F.sub.10 (The present                                                                  --    Zn-1.0                                                                              Pb-1.0  100  100 100 33                                  invention)                                                                    G.sub.1 (The present                                                                   --    Zn-1.0                                                                              Na-0.5, Mg-0.5                                                                        100  100 100 70                                  invention)                                                                    G.sub.2 (The present                                                                   --    Zn-1.0                                                                              K-0.5, Ca-0.5                                                                         100  100 100 100                                 invention)                                                                    G.sub.3 (The present                                                                   --    Zn-1.0                                                                              K-0.5, Cr-0.5                                                                         100  100 100 100                                 invention)                                                                    G.sub.4 (The present                                                                   --    Zn-1.0                                                                              K-0.3, Fe-0.5                                                                         100  100 100 85                                  invention)                                                                    G.sub.5 (The present                                                                   --    Zn-1.0                                                                              K-0.3, Ni-0.5                                                                         100  100 100 100                                 invention)                                                                    G.sub.6 (The present                                                                   --    Zn-1.0                                                                              Mg-0.5, Co-0.5                                                                        100  100 100 96                                  invention)                                                                    G.sub.7 (The present                                                                   --    Zn-1.0                                                                              Mg-0.5, V-0.5                                                                         100  100 100 90                                  invention)                                                                    G.sub.8 (The present                                                                   --    Zn-1.0                                                                              Ca-0.5, Cr-0.5                                                                        100  100 100 100                                 invention)                                                                    G.sub.9 (The present                                                                   --    Zn-1.0                                                                              K-0.5, Mg-0.5,                                                                        100  100 100 100                                 invention)           Fe-0.5                                                   G.sub.10 (The present                                                                  --    Zn-1.0                                                                              Mg-0.5, Cr-0.5                                                                        100  100 100 100                                 invention)                                                                    G.sub.11 (The present                                                                  --    Zn-0.2                                                                              K-0.3, Pb-0.5                                                                         100  100 100 45                                  invention)                                                                    __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                                  Percent removal of HCl and Cl.sub.2 at                                        the elapsed time shown below (%)                                    Adsorbent No.                                                                             10 hrs.  20 hrs.   40 hrs.                                                                             60 hrs.                                  ______________________________________                                        A.sub.0                                                                            (Control)   85       40      12    2                                     A.sub.1                                                                            (Control)  100      100      85    12                                    A.sub.3                                                                            (Control)  100      100      62    8                                     A.sub.9                                                                            (Control)  100      100      50    5                                     A.sub.12                                                                           (Control)  100      100      85    0                                     B.sub.2                                                                            (The present                                                                             100      100     100    65                                         invention)                                                               B.sub.3                                                                            (The present                                                                             100      100     100    40                                         invention)                                                               C.sub.4                                                                            (The present                                                                             100      100     100    88                                         invention)                                                               C.sub.6                                                                            (The present                                                                             100      100     100    35                                         invention)                                                               C.sub.9                                                                            (The present                                                                             100      100     100    59                                         invention)                                                               D.sub.2                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               D.sub.3                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               D.sub.8                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               D.sub.10                                                                           (The present                                                                             100      100     100    93                                         invention)                                                               D.sub.12                                                                           (The present                                                                             100      100     100    58                                         invention)                                                               D.sub.13                                                                           (The present                                                                             100      100      98    30                                         invention)                                                               D.sub.14                                                                           (The present                                                                             100      100     100   100                                         invention)                                                               D.sub.15                                                                           (The present                                                                             100      100     100   100                                         invention)                                                               E.sub.2                                                                            (The present                                                                             100      100     100    70                                         invention)                                                               E.sub.3                                                                            (The present                                                                             100      100     100    90                                         invention)                                                               E.sub.4                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               F.sub.1                                                                            (The present                                                                             100      100     100    65                                         invention)                                                               F.sub.6                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               F.sub.9                                                                            (The present                                                                             100      100     100    95                                         invention)                                                               G.sub.1                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               G.sub.2                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               G.sub.3                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               G.sub.6                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               G.sub.8                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               G.sub.9                                                                            (The present                                                                             100      100     100   100                                         invention)                                                               ______________________________________                                    

EXAMPLE 3

Packed into columns of 1.6 cm in diameter made of glass were 15 ml ofeach of the adsorbents of Example 1, A₀, A₁, A₃, A₁₂, B₂, C₄, C₉, D₃,D₈, D₁₃, D₁₅, E₂, E₄, F₆, G₁, G₃ and G₁₀, and a gas (97.5 vol. % of N₂and 2.5 vol.% of H₂ O) containing 20 ppm of HCl and 10 ppm of Cl₂, a gas(97.5 vol.% of N₂ and 2.5 vol.% of H₂ O) containing 20 ppm of HBr and 10ppm of Br₂, and a gas (97.5 vol.% of N₂ and 2.5 vol.% of H₂ O)containing 20 ppm of HI and 10 ppm of I₂ were passed through theindividual columns at a linear flow rate of 40 cm/sec at 250° C.,respectively, to determine the lengths of time until HCl--Cl₂ (convertedto the total Cl), HBr--Br₂ (converted to the total Br) and HI--I₂(converted to the total I) leaked respectively out of the columns (i.e.,the lengths of time required until the respective removal ratios reached95%). The results are shown in Table 3.

                  TABLE 3                                                         ______________________________________                                                    The length of                                                                            The length of                                                                            The length of                                           time for   time for   time for                                                which the  which the  which the                                               removal    removal    removal                                                 percentages                                                                              percentages                                                                              percentages                                             for HCl, Cl.sub.2                                                                        for HBr, Br.sub.2                                                                        for HI, I.sub.2                             Adsorbent   reached 95%                                                                              reached 95%                                                                              reached 95%                                 No.         (hrs.)     (hrs.)     (hrs.)                                      ______________________________________                                        A.sub.0                                                                            (Control)   2          3        5                                        A.sub.1                                                                            (Control)  14         18       29                                        A.sub.3                                                                            (Control)  12         13       14                                        A.sub.12                                                                           (Control)  15         20       28                                        B.sub.2                                                                            (The present                                                                             42         55       68                                             invention)                                                               C.sub.4                                                                            (The present                                                                             47         50       55                                             invention)                                                               C.sub.9                                                                            (The present                                                                             46         53       61                                             invention)                                                               D.sub.3                                                                            (The present                                                                             70         78       80                                             invention)                                                               D.sub.8                                                                            (The present                                                                             65         85       78                                             invention)                                                               D.sub.13                                                                           (The present                                                                             43         51       58                                             invention)                                                               D.sub.15                                                                           (The present                                                                             103        109      110                                            invention)                                                               E.sub.2                                                                            (The present                                                                             40         55       65                                             invention)                                                               E.sub.4                                                                            (The present                                                                             68         88       90                                             invention)                                                               F.sub.6                                                                            (The present                                                                             51         62       75                                             invention)                                                               G.sub.1                                                                            (The present                                                                             42         59       78                                             invention)                                                               G.sub.3                                                                            (The present                                                                             72         90       92                                             invention)                                                               G.sub.10                                                                           (The present                                                                             70         90       95                                             invention)                                                               ______________________________________                                    

What is claimed is:
 1. A method for the removal of halogens and/orhydrogen halides from a gas containing the same, which comprisescontacting the gas with an adsorbent comprising an activated carbonhaving as supported thereon ( 1) one or two components included in GroupI below and (2) one or more components included in Group II below:

    ______________________________________                                        Group      Component                                                          ______________________________________                                        I          copper oxide and zinc oxide                                        II         (a) alkali metal oxides                                                       (b) alkaline earth metal oxides                                               (c) oxides of Al, Ti, V, Cr, Mn, Fe, Co,                                         Ni, Cd and Pb                                                   ______________________________________                                    


2. A method as claimed in claim 1, wherein the one or two componentsincluded in Group I are copper oxide.
 3. A method as claimed in claim 1,wherein the one or two components included in Group I are zinc oxide. 4.A method as claimed in claim 1, wherein the one or two componentsincluded in Group I are copper oxide and zinc oxide.
 5. A method asclaimed in claim 1, wherein the activated carbon is one having assupported thereon copper oxide, zinc oxide and potassium oxide.
 6. Amethod as claimed in claim 1, wherein the activated carbon is one havingas supported thereon copper oxide, calcium oxide and potassium oxide. 7.A method as claimed in claim 1, wherein the activated carbon is onehaving as supported thereon zinc oxide, calcium oxide and potassiumoxide.
 8. A method as claimed in claim 1, wherein the gas is contactedwith the adsorbent at a temperature not higher than 600° C.
 9. A methodas claimed in claim 1, wherein the gas is contacted with the adsorbentat a temperature ranging from 0° C. to 300° C.
 10. A method as claimedin claim 1, wherein each of the components is supported on the activatedcarbon so that the amount of the copper oxide included in Group I, whenused, is in the range of from 0.1 to 3.0 mg-atom as metal per g ofactivated carbon, the amount of the zinc oxide included in Group I, whenused, is in the range of from 0.1 to 3.0 mg-atom as metal per g ofactivated carbon, and the total amount of the components included inGroup II is in the range of from 0.1 to 5.0 mg-atom as metal per g ofactivated carbon.